Diaphragm pump



Feb. 17, 1959y c. L. PRITCHARD DIAPHRAGM PUMP Filed May 12, 1955 /NUl/Tv/Q. lm/12ML Marl By QW TTR/Vfy I l I I I l I I Il 2,873,687 DIAPHRAGM APUMPv Clarence L. Pritchard, San Leandro, Calif., assignor to y Malsbary Manufacturing Company, Oakland,"Calif., a corporation of California Application May 12,119.55,.Sgerialy No. 507,880V 4 Claims. (Cl. 103-150) The present invention relates to improvements in a diaphragm pump, and its principal object is to provide a heavy rubber bumper for cushioning the drive strokes of the diaphragm and for effecting the return stroke.

It is a further object of the invention to substitute the heavy rubber bumper for `the spring previously employed for this purpose, since it has been found that the vrub-` ber bumper offers certain advantages over the spring in. smoothness .of operation, durability andei'e'ctiveness.

It is a further object of my invention to provide. means; f or mounting the rubber bumper with respectto the di aphragm whereby the bumper may be readily clampedx upon'the diaphragm in .a'single vmovement'and'may as easily` be' removed for replacement purposes.

manner that it becones part of the latter, `and that the It is additionally proposed to provide means' vfor sle-l. curing the rubber bumper to, therdiaphragm ini such ya 2,873,687 Patented Feb. Y l 7, 1 959 ICC ange 17 to provide an annular pocket in opposing and `spaced relation to the central section of the diaphragm.

The sleeve 14 is formed, below the waist, with a series of openings allowing liquid to pass therethroughiinto the sleeve for final discharge through the outlet 10.

The inner portion of the diaphragm, which is made of flexible material, preferably rubber reinforced by ber, is made to flex back and forth in a reciprocating movement in the operation of the pump. It is provided with a drive plate 18 having a flat bottom face 19 and an upper face which is flat in its central sectionl and diaphragm and the bumper become a single unit for ease. l

i-n assembling; operations.

And iina1ly it is proposedto providea-xed seat-ron; the pump chamber for; thexbumper tor bear, against, the, seat being formed with an annularilange for confining;

thefree end of the bumper.

Further objects and advantages of my invention will appearvv as the specification proceeds, and the new.v and` useful features of the samerwill be' fully dened in the,

claims attached hereto.

The preferred form of mytinventiornlfis illustrated in the accompanying drawing, forming part of this 'application,inwhich: v f l Figure 1 showsan axial section through a diaphragm pump having my rubber bumper incorporated therein;

"Figure 2,a vertical centralvsection through the `bumper;

Figure 3, aplan view of the bumper. f

While I have shown Only the preferred form of my invention, it should be understood that various changes or modifications may be made within'the scope of the claims attached hereto, without departing from the spirit of the invention.

Referring to the drawing in detail, vmy diaphragm pump 1 may be of any suitable or preferred construction, and is here shown as comprising a housing 2 including a lower section 3, an upper section 4, and a diaphragm 5 of conventional construction clamped between the two sections by means of bolts 6 extending through registering flanges 7.

The diaphragm may have an outer ring 8 encircling the same.

Thevupper section of the housing forms the pump chamber and has aninlet port 9, controlled by a suitable intake valve (not shown) and an outlet port 10, controlled by the discharge valve 11, which is normally l forced upon the valvel seat 12 by means of a spring 13.

to form a un-it therewith by shaping the bottom of the* tapered in its outer section 21.

A washer plate 22, co-extensive in diameter with the hat section' 20, is mounted on top of the central portion of the diaphragm.

The two plates 18 and 22 are held in assembled relation with respect to the diaphragm by means of an axial bolt 23, which has a head 24 bearing against lthe bottom face of the driving plate 18, extends through the assembly and has a nut 2S threaded upon its upper end and bearing upon the washer plate 22.

The extreme end' of the bolt shank projects slightly above the nut, when the latter is screwed home, asV at 26. Between the upper washer plate 22 and the bottom `face of the sleeve 14, there is mounted a heavyblock 27 of compressible rubber, whichpin its Afree state is prefer.-` ably conical in form, as shown in Figure 2,v andl which has a lower diameter equal to that of the washer 22 and an upper diameter corresponding to the inner diameter o f the flange 17. y

When'the diaphragm isat the end ofthe suction stroke,V the rubber body 27, which is hereinafter referred to, asI the bumper, extends from the Washer 22"into the pocket. defined by the flange 17 While retaining its conical' form but still preferably under slight'compression.`

During the compression stroke of the diaphragm, the bumper expandssidewise to bulge out as shown in Figure 1 and to build up pressure for then return orv suction` stroke. f

The bumper is secured .upo'n the diaphragm assembly" y bumper with a recess 28 having a tight, clamping fit with the nut 25 and a reduced extension recess 29"itti'n'g' tightly on the Yextremity 26 of the bolt shank. A Thus, the bumper may be readily appliedbyfpr'essing" .n.1 therecessed'r bottom upon the nut and they endv of the.

bolt. y

VThe drive for the power s'trokeis conventional1v 'ande4 comprisesv a shaft 30 mounted transversely in the lower.` housing section 3, in bearings 31 and having a central.L

i eccentric section 32' between the bearings.

A tire 33 is mounted on the eccentric section, through a bearing 34 and contacts the bottom face of the bolt head 24, the various parts being located and dimensioned so that on the power stroke, the eccentric exes the diaphragm upward as shown in Figure l, while on the suction stroke it allows the bumper to flex the diaphragm downward. e

The shaft may be revolved by any suitable means, as by the pulley 35.

In operation:

As the eccentric rotates through a one-half revolution from the position shown in Figure 1, it frees the diaphragm for downward movement, and the bumper, exerting downward pressure on the diaphragm, ilexes the latter downward while the bolt head remains in contact Y with lthe eccentric tire.

During vthis stroke, the discharge valve 11 closes, 'and the intake valve opens, causing liquid to en ter into the v pump chamber through the port 9.

and to compress the bumper into the form shown in Figure 1. The diaphragm forces the liquid present inthe pump chamber through the outlet valve 11, while closing the intake valve forv portk 9. j

I"Thus the blmper'serves to cushion the drive stroke, to. elect the suction stroke and to insure a smooth transition from one stroke to the other.

The bumper may be easily applied in a single movement by merely pressing it upon its seat and it becomes then apart of the diaphragm assembly. It may also be easily removed for replacement purposes and is wearresistant under the conditions prevailing in a pump chamber to a much greater degree than any metallic spring used for the same purpose.

` In pumps of the character described, it is customary to provide a metering valve in the intake so as to allow the volume of discharge to be controlled. This makes it desirable to limit the suction stroke to the exact amount gf water available for fill-ing the pump chamber in order to prevent the creation of-a Vacuum which would cause a portion of the water to be vaporized.

In order to accomplish this, I make the rubber material of the bumper sufficiently soft, as related to the size of the body and the diameter of the diaphragm to cause the bumper to` automatically `limit 'the 'suction stroke to the amount ofwater available, 'and I rind that in the pump in 'actual operation a rubber body of a durometer reading of 45 to 50 gives satisfactory results.

When the suction stroke is thus limited, it is apparent that the bolt head 24 temporarily loses contact with the eccentric tire.` l

I It should also be noted that the diameter of the bumper should be suiiciently large, as compared with its length, to prevent buckling of the bumper during the operation of the pump. i

The conical form of lthe bumper further aids in stabilizing the bumper and in preventing sidewis'e bending oi the same under compression.

I claim: v

l. A diaphragm assembly for a diaphragm pump, cornprising a discl diaphragm made of resilient material, a drive plate mounted on one side of the diaphragm, a washer plate mounted upon the second side of the dia phragm, a bolt extending axially through the plates and the diaphragm and having a head bearing against the drive plate and having a threaded shank projecting beyond the washer plate, a nut threaded on the projecting end of` the shank for clamping the plates upon the diaphragm, theshank having an extremity projecting beyond the nut, and a rubber bumper having one end bearing upon the washer plate and having a stepped recess in said end for clampingly engaging over said nut and the extremity ot the shank.

2. In a diaphragm pump, a housing having a pump asvaesv chamber with an intake port and an exhaust port, a dia- "phragm mounted in the wall of the chamber with freedom of reciprocating movement for alternate drive strokes and suction strokes, an abutment mounted in the chamber in spaced and confronting relation to a central section of the diaphragm and free to allow liquid to pass around the same, means active on the diaphragm for effecting the drive strokes, and a heavy solid rubber bumper interposed between the abutment and the diaphragm and adapted to be compressed by the drive strokes and to eiect the suction strokes, the diaphragm having plates on opposite sides thereof, a bolt extending through the plates and the diaphragm, and a nut threaded upon the bolt from the inside of the chamber, and the rubber bumper having a socket in the lower Yportion thereof adapted for clamping upon the nut to cause the bumper to become a fixed part of the diaphragm, with the major portion of the bumper projecting above the nut.

3. In a diaphragm pump, a housing having a pump chamber with an intake port and an exhaust port, a diaphragm mounted in the wall of the chamber with freedom of reciprocating movement for alternative drive strokes and suction strokes, an abutment mounted in the chamber in spaced and confronting relation to a central section of the diaphragm and free to allow liquid to pass around the same, means active on the diaphragm for electing the drive strokes, and a heavy solid rubber bumper interposed between the abutment and the diaphragm and adapted to be compressed by the drive strokes and to etect the suction strokes, the bumperv and the diaphragm'having cooperative means for clamping the' lower end of the bumper upon the diaphragm, and the abutment having an annular flange adapted for receiving the upper end of the bumper therein. i

4. A diaphragm assembly for a diaphragm pump, comprising a disc diaphragm made of resilient material, a drive plate mounted on one side of the diaphragm, a

- washer plate mounted uponrthe second side of the diaphragm, a bolt extending axially through the plates and the diaphragm and having a head bearing against the drive plate and having a threaded shank projecting beyond the washer plate, a nut threaded on the projecting lend ingly engaging over the nut.

References Cited in the iilerof this patent UNITED STATES PATENTS France .f June 23, 19,54-I 

